| Object:In order to clarify the operation parameters of UAV spraying and the best mode of UAV liquid-assisted pollination operation in different periods of the compact planting of Korla fragrant pear orchards in Tumushuke,Xinjiang,and to screen the best pesticides to control the two main pests of pear orchards,psyllas and spider mites.Methods:Taking the compact planting of fragrant pear orchards around Tumshuke City as the research object,the XAG Xp20 quadrotor electric plant protection UAV was selected as the spraying device.A three-level orthogonal test combination was carried out with three factors of flight height,spray volume and flight speed,and the optimal flight parameters of UAV spraying operation in different periods of compact planting Korla fragrant pear orchard were selected by taking the deposition density,coverage rate and uniformity of droplets of pollination fluid and spray solution as evaluation indexes.By comparing flight parameters,flight trajectories,pollination volume,fruit setting rate,and fruit quality of fragrant pears under different pollination methods,the optimal operation parameters of UAV liquid-assisted pollination were determined.By evaluating the yield and economic benefits of different pollination methods,the feasibility of UAV liquid-assisted pollination technology promotion was explored.At the same time,the types and dosages of pesticides most suitable for the control of psyllas and spider mites in fragrant pear orchards around Tumushuke city were screened.By investigating the receding rate of psyllas and spider mites after 1d,3d,7d and 14d of spraying with different concentrations of 7 pesticides.Results:1.The optimal flight parameters of the UAV for liquid pollination in compact planting Korla fragrant pear were the flight height of 1.5m,the spray volume of 60.0L·hm-2 and the flight speed of 3.0m·s-1;the optimal flight parameters of the UAV flight defense were:the flight height was 2.5m,the spray volume was 60.0L·hm-2 and the flight speed was 2.5m·s-1.2.The fruit-setting rate and yield of liquid-assisted UAV pollination were better than those of other parameter combinations at the flight altitude of 1.5m,spray volume of 60.0L·hm-2 and flight altitude of 3.0m·s-1.The flight height was the main flight parameter affecting fruit quality,and the test results showed that height was inversely related to single fruit weight,hardness and Vc content of fragrant pears.There was no significant effect of different flight trajectories on fruit set and yield,but the fruit quality was better when the flight trajectories were flown between the rows of trees.Fruit set and yield were positively correlated with pollination dosage,with the highest fruit set and yield achieved at 270 g-hm-2.The amount of pollination had a significant effect on fruit weight,hardness and fruit shape index,and the best fruit quality was achieved at pollination rate of 270g·hm-2.The recommended liquid pollination dosage for UAV is 270g·hm-2.3.The fruit set rate,yield and quality of liquid pollination using UAV for two times and one time of manual supplemental pollination were not significantly different from those under manual spot pollination and manual backpack liquid pollination.The total cost was 4890 yuan·hm-2,which was 2782.2 yuan·hm-2 and1170 yuan·hm-2 lower than that of artificial dusting and artificial backpack liquid pollination,respectively.The net income per unit area can reach 105738.94 yuan·hm-2,with 30min·667m-2 of labor time,which can meet the requirements of fragrant pear production.4.The control effect of 8%lambda-cyhalothrin was the best and lasted for a long time.Its control effect is as high as 86.85%after 14 days of treatment,followed by 5%aminoabamectin benzoate and 21%thiamethoxam.70%imidacloprid has the worst control effect,and its control effect is 50.89%after 14 days.20%ave-etoxazole and 5%fenpyroximate had better quick-acting effects on spider mites control,and the control effect after 3 days of application were 74.91%and 81.43%,respectively.In addition,after 14 days of 20%avi-etoxazole,5%fenpyroximate and 20%avi-spiroxafen,the control effect reached more than 80%. |
